On the widget view for the outlook app on Android. The ability to view the entire month instead of just the upcoming events in the week. Something similar to what Google Calendar is able to accomplish as they can show the moth view in their widget view on the main screen of the phone.

This was something easily done with Exchange accounts. I am still bewildered as to why it was left out of O365. This also means you cannot subscribe to calendar notifications separately on a watch. You can only subscribe to all Outlook notifications. This is a serious shortcoming.